Hey, I have been lurking the forums for quite a while now and I've finally came across an issue that I needed to post for. So I just made an account today haha.

Okay, so I have an '05 Evo 8 MR. When I got it, it had a Hallman MBC set to 20psi. The factory BCS was still plugged in, but the plastic hose nipples were cut and melted shut. Just recently I bought a Grimmspeed 3-port and set it up correctly per provided instructions but couldn't get it to work. It would just run wastegate pressure. My friend that was street tuning my car even attempted to max out the low gear duty cycle table values just to confirm that it isn't doing anything (lol yolo). Then I switched the hoses for WG and boost source in case I somehow manage to mess up a noobproof installation procedure. That didn't change anything, so I switched it back. I emailed Grimmspeed and they suggested wiring it up to a 12v source to see if it even actuates, which makes an audible click. I tested that and it indeed clicks. I was thinking maybe the previous owner did something to the wiring.

My question is: is there something common, that I'm missing, that people do to your factory BCS wiring when setting up a MBC on these cars?

 

Can you post up how you have the hoses ran?

 

Sure thing!
Although I don't have a picture readily available, I know that port 3 (middle port) was routed to a boost source via the nipple on the compressor housing and port 2 (left port) was routed to the wastegate while port 1 vented to atmosphere.

 

Here is how it sits now. It isn't hooked up right now, I actually went back to the Hallman MBC in the meantime.